OPERASI-OPERASI PERMESINAN

1Operasi Permesinan

Operasi Permesinan 2

Turning

N = rotational speed, rev/minv = cutting speed, m/minD0 = original diameter, mm

Df = final diameter, mm

d = depth of cutf = feed, mm/revfr = feed rate, mm/min

Tm = time of actual machining, min

L = length, mmMRR = material removal rate mm3/min

Dv

N0

dDD f2

0

Nffr

fTr

m

L vfdMRR

Operasi Permesinan 3

Operasi Turning Lainnya

(a) facing (b) taper turning (c) contour turning (d) form turning (e) chamfering (f) cutoff (g) threading (h) boring (i) drilling (j) knurling

Operasi Permesinan 4

Mesin Lathe

Operasi Permesinan 5

Metoda Pencekaman Benda Kerja Pada Lathe

(a) mounting the work between centers using a “dog” (b) three-jaw chuck (c) collet (d)face plate for non cylindrical workparts

Operasi Permesinan 6

Contoh Urutan Operasi Turning

(1) feed stock to stop (2) turn main diameter (3) form second diameter and spotface (4) drill (5) chamfer (6) cutoff

Operasi Permesinan 7

Drilling

N = spindle speed, rev/minv = cutting speed, mm/minD = drill diameter, mmf = feed, mm/revFr = feed rate, mm/minTm = machining time, minT = work thickness, mmA = approach allowanceMRR = material rate of return

D

vN

Nffr fT

r

m

At

)2

90tan(5.0

DA fTr

m

d

4

2 fD rMRR

Operasi Permesinan 8

Operasi Drillling Lainnya

(a) reaming (b) tapping (c) counter boring (d) countersinking (e) center drilling (f) spot facing

Operasi Permesinan 9

Mesin Drilling

Drill press & Radial drill press

Operasi Permesinan 10

Milling

• Horizontal milling• Vertical milling

Operasi Permesinan 11

Horizontal Mill

Types of horizontal boring mill (a) boring bar is fed into a rotating workpart (b) work is fed past a rotating boring bar

Operasi Permesinan 12

Vertical Mill (2)

Vertical boring mill

Operasi Permesinan 13

Milling

Types of milling operation: (a) peripheral or plain milling (b) face milling

Operasi Permesinan 14

Peripheral Milling

(a) slab milling (b) slotting (c) side milling (d) straddle milling

Operasi Permesinan 15

Tipe Pemotongan Milling

(a) up milling (b) down milling

Operasi Permesinan 16

Face Milling

(a) conventional face milling(b) partial face milling (c) end milling (d) profile milling (e) pocket milling (f) surface contouring

Operasi Permesinan 17

Parameter Pemesinan Milling

• Nt = number of teeth

fT

fnf

r

m

r

tr

AL

dDdA

wdMRR

fN

D

vN

)(

Operasi Permesinan 18

Mesin Milling (1)

(a) horizontal (b) vertical

Operasi Permesinan 19

Mesin Milling (2)

(a) universal-overarm (b) ram type

Operasi Permesinan 20

Machining Centers

• Automated machine tool capable of performing multiple machining operation under CNC control, having features:

– Automatic tool-changing– Pallet shuttles– Automatic workpart

positioning

Operasi Permesinan 21

Turning Centers

Operasi Permesinan 22

Operasi pada Mill-Turn Centers

(1) turn second diameter (2) mill flat with part in programmed angular position (3) drill hole (4) cutoff

Operasi Permesinan 23

Operasi Milling Lainnya

(a) shaping (b) planning

Operasi Permesinan 24

Bentuk-bentuk Shaping & Planing

Operasi Permesinan 25

Mesin Shaper

Operasi Permesinan 26

Mesin Planer

Operasi Permesinan 27

Operasi Milling Lainnya

Broaching

(a) external broaching (b) internal broaching

Operasi Permesinan 28

Sawing

(a) power hacksaw (b) bandsaw (c) circular saw

Operasi Permesinan 29

High Speed Machining

Solid Tools (end mills, drill) Indexable Tools (face mills) Work Material Conventional

Speed (m/min) High Cutting

Speed (m/min) Conventional

Speed (m/min) High Cutting

Speed (m/min) Aluminum 300 3000 600 3600 Cast iron, soft 150 360 360 1200 Cast iron, ductile 105 250 250 900 Steel, free machining 105 360 360 600 Steel, alloy 75 250 210 360 Titanium 40 60 45 90